The present invention relates to computer systems and more particularly to a new type of interactive computer system for enabling a problem solving user to create (i.e. plan and evaluate) solutions to problems by building schematic diagrams representative of the solutions. The system of the present invention is useful in designing solutions which lend themselves to symbolic representation, e.g. in the form of schematic diagrams such as flow charts, process diagrams, and the like. Examples of designs which utilize such solutions are the layout of assembly lines for product manufacturing, the design of computer systems, computer software design, and the design of refineries and chemical plants. The interactive computer system disclosed herein also has application to the creation and use of "smart forms", e.g. for income tax reporting purposes, which are capable of satisfying the unique requirements of any problem solving user.
Past attempts to develop computer systems which are capable of creating problem solutions have been implemented through artificial intelligence techniques. Artificial intelligence is the branch of computer science that attempts to make machines emulate intelligent behavior. There has been success in enabling a computer to reason from knowledge in a limited domain, and in some instances computer programs implementing artificial intelligence techniques can exceed human performance. Such programs use a collection of facts, rules of thumb, and other knowledge about a given field, coupled with methods of applying those rules, to make inferences. These programs have been applied to such specialized fields as medical diagnosis, mineral exploration, and oil-well log interpretation. Since such programs often must make conclusions based on incomplete or uncertain information, they differ substantially from conventional computer programs which solve problems in accordance with pre-defined algorithms and complete data sets. The power of such systems results from entering large amounts of knowledge into the computer. It is such knowledge data, and not sophisticated reasoning techniques, that is responsible for the success of such "expert" systems. An introduction to such systems is provided in the article entitled "Expert Systems: Limited But Powerful", by William B. Gervarter, IEEE Spectrum, August, 1983, pgs. 39-45.
One problem with knowledge based expert systems is the vast amount of data which must be entered into the computer in order to provide a useable system. The more knowledge a system is given, the better will be its solution. There is a tradeoff, however, because greater search time is required when more information is entered into the system. Other drawbacks to such systems are their narrow domain of expertise, the requirement that problem solving users describe problems in a strictly defined formal language, and the extensive training required to teach problem solving users to use such systems.
The present invention provides a general purpose machine for designing problem solutions which can be represented in schematic diagram form, and avoids many of the problems associated with prior knowledge based systems. Although the system can be used to build problem solutions in any field in which solutions can be represented in schematic form, the system will be described herein primarly with reference to the automation of the proces used by programmers, data processing analysts, and system methodology designers to create computer software for commercial applications. The description of the invention in connection with the creation of computer software is not intended to limit the scope of the invention in any manner. Those skilled in the art will appreciate that as a general purpose system, the apparatus and techniques of the present invention will have broad application to the design of problem solutions in any field where such solutions can be represented in schematic diagram form.
Current methods of software design are time consuming and unsuitable for collaboration between many people. It would be advantageous to provide tools for software creation professionals which allow them to employ techniques derived from the world of computer aided design and engineering. These techniques would be utilized to create the logical analysis of the system whose design is being sought, to plan the solution itself, to identify the parts of the solution that can be implemented as independent modules, to identify the elements of communication between such independent modules in the solution's implementation, to design the independent solution components, and to test for their logical correctness prior to actually including the design solutions in a computer program. It would also be advantageous to be able to utilize functional modules previously designed in the context of other solutions for other problems, in the solution effort for the problem at hand. Such re-utilization of previously developed modules would increase the efficiency of the design process. The present invention relates to such a system.
In the system of the present invention, problem solutions can be generated in schematic diagram form in accordance with certain methodologies. The solutions are such that information can be extracted from a design at a graphical level and be used as the basis for subsequent input to automatic code generation tools or other automated functions, such as the generation of masks for fabricating integrated circuits. The system enables problem solving users to initially sketch what they conceive to be their current notion of a possible solution strategy. This mode of system use is referred to as the "chart" mode. After the sketching process has led to some degree of satisfaction and acceptance of the solution strategy, a formal rule-based schematic of the solution can be created which logically conveys each aspect of the solution prior to its implementation. The creation of such schematics occurs at the "schematic" level of the system. The formal schematic is then reviewed by the system to verify that it is correct with regard to all of the internal formal rules, details and mechanisms of the methodology that is employed to create it.
A key function of the present invention is the provision of means for enabling a methodology designer to create a library of logically or methodologically based schematic symbols, or graphic icons, and related formal functions which govern the employment and manipulation of the graphic icons when combined into a problem solution. The icons and functions ar created by the methodology designer on an interactive basis with the system. Thus, during the creation of such icons and functions, the system prompts the methodology designer to identify, by way of example, the parameters and use of each icon or function. On the basis of these parameters, the system generates and stores a specific set of rules for each and every icon and function which completely and logically establish how each icon and function can be used to build problem solutions. In prompting a methodology designer to identify such parameters, the system requires the methodology designer to provide examples as to how the icon or function being created can be connected to other icons and/or functions. Such examples enable the system to generate the specific rules for the use of the icons and functions. Thus, the rules are built "by way of example".
As noted, the methodology designer can create new graphic icons and new formal functions. The new functions can be represented either in a text format or symbolically as "function icons". Such new functions can be built in three ways, to be explained hereinafter in detail. In general, these three methods comprise (1) concatenating function primitives already stored in the system; (2) concatenating function primitives with other existing complex functions; and (3) creating value tables for a function icon by assigning input and output values to all of the open ended connectors present on the function icon, which values are used by the system to establish a transfer function across the icon. The types of values which can be assigned when creating value tables are actual numerical values, indirect values (i.e., pointers to actual values), and inputs or outputs of other functions.
Unlike prior knowledge based systems, which require the entry and storage of a vast amount of information, the system of the present invention builds rules on the basis of procedure within a field of intent. Each such field of intent may be represented by its own library of icons and functions within the system. The system thereby precludes interference between intents. Since a methodology designer can create unique sets of icons and functions to accomplish desired intents from axiomatic primitives stored in the system, a truly general purpose machine results. Once a methodology designer creates a special library of icons and functions for a desired application (i.e., intent), the system can then accommodate any problem solving user who desires to build problem solutions for that application in schematic diagram form. The methodology designer has complete control over what applications the system can be used for and in the definition of the methodology to be used in building solutions for those applications. This is a substantial advance over prior systems, which can be used only for the creation of problem solutions according to an established methodology in the specific field in which the machine is "knowledgable".